£? 



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*79 






ACCOUNT 

OF AK 

IMPROVED 



By T.' SOP WITH, F. G. S. 



DESCRIPTION AND USE 



OF 



AN IMPROVED 



ILH^HtLOUQKl© ©T^^Ic 



BY T. SOPWITH, F. G. S., 

LAND AND MINE SURVEYOR, 
MEMBER OF THE INSTITUTION OF CIVIL ENGINEERS. 



t* PRINTED FOR THE AUTHOR. 



<S 7 



$ 



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DESCRIPTION AND USE 



OF AN IMPROVED 



LEVELLING STAVE. 



The process of levelling is one which necessarily 
requires great care in the operation, and great 
accuracy in the instruments used. In surveying 
and setting out many of the principal roads through- 
out the kingdom, and especially cross country 
roads, levelling has not been resorted to as a 
preliminary measure, but mere caprice or imaginary 
convenience has determined what course should be 
pursued. Of late years, however, a different and 
more improved practice has prevailed. Not only 
have the lines of country through which it is 
proposed to form new roads been carefully sur- 
veyed, but in most instances accurate levels have 
been made of the surface, and the lines of road 
varied as considerations of distance and levels 
required. In the surveys of roads made under 
the direction of government, exact sections of 
the present and proposed lines form an important 
and essential feature; and it is desirable that 
the forms of Parliament should render sections 
requisite in all legislative enactments for making 
new turnpike roads, or amending or altering old 



ones. In applications for railway acts, sections 
are absolutely necessary, and the standing orders 
of Parliament require that they shall accompany 
the plans of such proposed railways. In agricul- 
tural pursuits, and especially as regards drainage, 
it is frequently essential that the surface of grounds 
should be accurately levelled ; and, for many pur- 
poses connected with geology and mining, exact 
levels of the surface of districts are often required. 
In most of these departments, it is not only neces- 
sary that a tolerably exact approximation be made — 
a rigid accuracy is often required, which can only 
be attained by great care in the operation, and by 
the use of correct instruments. In some subterra- 
nean works it is requisite that a series of levelling 
operations, carried over several miles of country, 
both above and below ground, should be exact to 
a few inches ; and in the conveyance of water by 
aqueducts, as in the sewers of a level district, it is 
necessary that the work be conducted from details 
which can only be procured by very careful and 
exact levelling. Important errors in levelling have 
frequently arisen; sometimes, in public works, 
these errors have caused a great and needless 
expenditure ; and in private practice it is difficult 
to say how much inconvenience and loss have 
resulted from this cause. It is evident that the 
time of any person who is competent to take levels 
with sufficient exactness must be valuable, either 
as it regards public or private works; and whatever 
tends to shorten the time and increase the accuracy 



of those who are employed in such operations, 
must be an improvement deserving* the attention 
of professional persons. 

Such is the object of the Improved Levelling 
Stave; and with a view to its being rendered as 
useful as possible, I shall endeavour, as concisely 
as I can, to point out what I conceive to be its 
advantages. 

The Levelling Staves in general use are of 
various forms, especially as regards the number of 
slides, and the index or scale by which the eleva- 
tions or depressions are read off. They consist 
sometimes of one, but more commonly of two or 
three rods, figured from the bottom, and sliding so 
as to form a convenient length for being carried 
from place to place. The most common construc- 
tion is as follows : — A rod of 5 or 6 feet is made 
to receive one or two other rods, which slide within 
it. On the outer rod is a graduated scale of figures, 
either in twelfths or tenths of a foot, as the practice 
of the surveyor may be; some using inches or 
twelfths of a foot, and others tenths or decimals. 
Upon this rod a vane, or cross piece of wood, is 
made to slide, having black and white marks to 
make it conspicuous, and an aperture in the centre, 
through which the graduated scale may be seen. 
The assistant who holds the stave, after setting it 
steadily down, and holding it as upright as he can, 
keeps his eye on the observer at the level, and 
according to certain signals, commonly made by 
moving the arm, slides the vane up or down, until 



6 



by another signal, or a call if sufficiently near, he 
is apprized that the vane is in the right position. 
He (the assistant) then reads the scale through the 
aperture in the vane, and reports it to the surveyor 
or observer when he comes up ; and the observer 
himself generally examines the scale, in order to 
detect any mistake made by the assistant: but 
this precaution is sometimes neglected. 

In this practice, it is in the surveyor's power to 
examine the stave, provided he can depend on the 
position of the vane being exactly as it was when 
he beheld it through the telescope of his level; 
and if, on examination, it appears the same as the 
assistant reports his observation, it amounts nearly 
to a demonstration of the accuracy of the observation. 
In the survey of roads and railways, however, it 
not unfrequently happens that matters are deferred 
until the latest possible opportunity, and the sur- 
veyor is compelled to hurry forward both his 
surveying and levelling operations in the most 
rapid manner he can devise, consistently with their 
proper execution. In this and similar instances, 
where expedition is required, it is usual to carry 
on the levelling process with two staves, one behind 
and another before the observer, so that what are 
called the rear-sight and fore-sight may be taken 
without the delay occasioned by the assistant's re- 
moving from one to the other. In this case, though 
the surveyor may examine the fore-sight stave, he 
cannot see the rear-sight one until it has been 
carried a considerable distance j and even the time 



to examine the fore-sight stave can hardly be 
spared in expeditious levelling. It will also be 
readily understood, that the operation of moving 
a vane slowly up or down until its centre line 
exactly coincides with so delicate an object as the 
cross-hair in a telescope, is one which occupies much 
time, and requires no small share of patience, both 
in the surveyor and the assistant; and the nearer 
the approximation becomes, the more difficult is it 
to obtain that close coincidence which is requisite* 
When the observation to be taken exceeds the 
height of the first stave, it becomes necessary for 
the assistant to remove the vane, and to fix it on 
the moveable rod, which he then slides up to the 
required height, and reads the elevation by means 
of an index or graduated scale. Here a new source 
of difficulty and delay often arises. If the sliding 
rod moves too freely, it is sometimes next to impos- 
sible to shift it steadily down to read the index ; 
and if it moves too stiffly, much time is lost before 
the sudden and awkward jerks which propel it allow 
it to coincide with the cross-hair of the levelling 
instrument. To some these details may appear 
prolix, but those who have had occasion to take 
extensive ranges of levelling must have found that 
these hinderances often cause great inconvenience, 
and always great loss of time. Sometimes, in 
extensive surveys, it is difficult to procure assistants 
competent to read the graduations of the scale with 
sufficient exactness, and if through inadvertence, 
or the slackness of the instrument, any change of 



8 



the vane or sliding rod occurs, the surveyor may- 
experience all the disadvantage and delay of a 
material error, which, if not detected in time, may 
occasion great embarrassment and delay. A very 
hot day may cause the rods to slide very easily, 
and an occasional shower of rain make them so stiff 
as to be moved with difficulty; and these disadvan- 
tages attach, more or less, to most of the levelling 
staves commonly used. 

The construction of the Improved Levelling 
Stave is such that the surveyor reads for himself at 
the very moment of taking the observation. The 
assistant is not required to give any attention to 
this part of the operation, and therefore no mistake 
can possibly arise from his ignorance or inattention. 
No time is lost in moving a vane up and down, as no 
vane is required; for as soon as the level is adjusted 
the surveyor has only to look through the telescope, 
and he perceives at once the cross-hair intersecting 
the broad and clear graduated scale of the levelling 
stave. He has only, therefore, to assure himself 
that his instrument is truly level, to mark down 
the elevation, and proceed with confidence and 
expedition unattainable by the ordinary methods. 
Another great advantage in the construction of 
the Improved Level is, that the sliding rods may 
always be kept so slack as to slide with great 
ease, being fastened at the correct elevation by a 
spring with a catch, which, when fixed, prevents 
them from moving. The height is not obtained 
by sliding the rods or a vane up and down, but 



9 



they are placed at once, by means of the spring, at 
their full height, and having a graduated scale, 
which is a continuation of the lower one, the sur- 
veyor reads the figures on them in the same manner 
as on the lower part of the stave. In levelling 
staves of this description I have seen the upper rods 
fixed by means of a small screw ; this, however, is 
liable to two objections. The screw is very apt 
to injure the rods as they slide, and the stave 
which I saw had in this manner become almost 
useless ; but the principal defect is, that it requires 
some time and attention to fix and unfix the screw 
properly, for if the rods be not very exactly placed, 
as regards the graduated scale, it is evident an 
error may arise without any chance of being 
detected. The application of a spring-catch com- 
pletely obviates these defects, the fixing is the 
work of a moment, and when fixed the rods cannot 
but be in a correct position, since the construction 
of the stave is so contrived as to effect this desirable 
result. 

However theory may seem in favour of this or 
any other improved instrument, practice is the best 
criterion, and by this test the superior advantages 
of the Improved Levelling Stave have been fully 
confirmed. Instead of a slow and tedious process, 
liable to uncertainty, the useful art of levelling is 
capable of being practised with great expedition 
and success. Time is in all circumstances valuable, 
but when levelling operations have to be carried on 
in a populous town it is of great importance that 



10 



each observation should be made as quickly as 
possible, for the sight which may be taken one 
minute may be interrupted by carriages or foot 
passengers the next. Instead of a tedious and 
uncertain process, the observer at a glance perceives 
the figures and scale of tiie index, notes them in 
his level-book, confiding in the correctness of his 
awn inspection, and proceeds without delay to take 
another observation. The Improved Levelling 
Stave is larger in dimensions, and consequently 
heavier, than those commonly used. The former 
is necessary in order to obtain a broad surface for 
the figures and scale, and the latter, without ren- 
dering the instrument incommodious, tends to give 
a greater degree of steadiness when exposed to a 
current of wind. It is also a great advantage that 
the attention of the person who holds the stave may 
be entirely directed to the single object of holding 
it in a perpendicular position, a condition highly 
essential to correct levelling, but which is very apt 
to be neglected when the assistant is occupied in 
the treble task of observing the signals of the sur- 
veyor, moving the vane, and attempting to main- 
tain the stave in a vertical position. The scales 
of feet on the face of the staves may be graduated 
decimally, or in inches, according to the practice 
of the surveyor who uses them. Either the one 
or the other may be read to the 100th or 120th of 
a foot, at the distance of five or six chains, and a 
tolerably correct approximation can be made at a 
greater distance; but whatever kind of stave is 



11 



used, no observation, in which tolerable exactness 
is required, should exceed the former distance, 
and, where minute accuracy is required, the dis- 
tance ought not to exceed two or three chains. In 
this case also the observer should be very careful 
to place the level as nearly as possible midway 
between the places of observation. 

Mahogany is the best wood that can be used in 
the construction of Levelling Staves. Plain or 
straight-baited wood, as workmen call it, should be 
selected, and it ought to be well seasoned. When 
made, the surface of the instrument should be 
saturated with linseed oil, and suffered to stand a 
few days, after which a final covering of French 
polish will render it impervious to the weather. 
Great nicety is required in setting off the scale, 
which is best done by means of an accurate feather- 
edged ivory scale and needle. The usual process 
of levelling is well known, and tables for correcting 
the curvature are to be found in many mathematical 
works ; but in so short a distance as is commonly 
taken in practical levelling, this correction is not 
required. If used at all, it is only to be applied 
to the difference of distance between the level and 
rear-sight, and that between the level and fore- 
sight, which, if the observer carefully selects his 
stations, will be either equal or very nearly so. 
When once the levelling instrument is adjusted, the 
observer may very quickly take several observations 
from one station ; thus obtaining a minutely accu- 
rate profile of the ground which, though valuable, 



12 



might not be sufficiently so, to repay the time and 
trouble it would take to obtain it by the ordinary 
method of a sliding vane. This facility of obser- 
vation renders the improved stave particularly ap- 
plicable to the exact measurement of such objects 
as have various elevations at a moderate distance. 
Thus, for taking the transverse section of a road 
or railway, the level may be placed either in a 
line with the proposed section, or in any other 
convenient position. A chain or tape-line being 
extended across the road, and the stave successively 
placed at each prominent part, the observer can 
note down the several elevations in his book almost 
as quickly as the stave can be placed, whereas, with 
a sliding vane, the moving of the slide and inspec- 
tion of the scale would, in each case, occupy as 
much time as by the other mode is required for the 
whole operation. 



Printed by W. Davison, Alnwick. 



RECENTLY PUBLISHED, 

AND SOLD BY THE AUTHOR, AT HIS OFFICE, 
ROYAL ARCADE, NEWCASTLE, 

AND BY ALL BOOKSELLERS. 



DEMY 8vo.,with 34 COPPERPLATE ENGRAVINGS, Price 16*. 

A TREATISE ON ISOMETRICAL DRAWING, as 
applicable to Geological and Mining Plans, Picturesque 
Delineations of Ornamental Grounds, Perspective Views 
and Working Plans of Buildings and Machinery, and to 
general Purposes of Civil Engineering; with Details of 
improved Methods of preserving Plans and Records of Sub- 
terranean Operations in Mining Districts. By T. Sopwith, 
Land and Mine Surveyor, Member of the Institution of 
Civil Engineers, Author of " Geological Sections of Mines/' 
"Account of Mining Districts," &c. 



OPINIONS OF THE PRESS. 

" The chapter on mineral plans is of very great value, both as to the 
minute and sensible details into which the author enters, repecting plans 
and the best mode of constructing them, the instruments to be employed 
in making them, and the best method of preserving mining plans and 
records. As to isometrical drawing, this work is by far the most 
complete that has appeared. Mr. Sopwith describes, in a clear and 
interesting manner, the great advantages of isometrical drawing in geology 
and mining, its application to ornamental and landscape gardening, in 
which he is supported by the high opinion of Mr. Loudon, and its use for 
plans of buildings and machinery and for general purposes of civil engi- 
neering. The copious illustrations, the many striking examples intro- 
duced, and the excellent engravings, make this work not only of importance 
to the man of science, but attractive to the general student. Indeed Mr. 
S. has so skilfully treated his subject as to remove all difficulties from any 
person of ordinary industry." — Tyne Mercury, 



" For landscape gardening, isometrical projection is as admirably adapted 
as it is for architecture ; and we cannot but recommend this book most 
strongly both to gardeners and land-surveyors. To land and mine 
surveyors it is indeed indispensable, nothing of equal importance to it 
having appeared since Mr. Horner published his Improved Method of 
Land-Surveying in 1810."— Loudon's Gardeners' Magazine. 

"On this useful mode of representing objects, Mr. Sopwith has the 
merit of producing the first work, or, at least, the first work of real use 
entirely devoted to the subject. We recommend this work for the 
accurate manner in which it is treated, as indispensable to engineers, 
architects, coal-viewers, and surveyors, and to every draughtsman em- 
ployed in delineation." — Newcastle Chronicle. 

" It gives exceedingly simple and easy rules and examples how to 
construct designs. No engineer, builder, or mining surveyor, or student 
in these professions, should be without this work."—'* The explanations 
of Mr. Sopwith are suited to the comprehension of the general reader, and 
the subjects treated of are exemplified in a familiar and easily comprehen- 
sible style." — Newcastle Courant. 

"We have only room, at present, strongly to recommend Mr. Sopwith's 

bOOk, as BY FAR THE BEST, AND INDEED THE ONLY COMPLETE WORK, 

that has yet appeared on the subject. Every part of it is rendered easily 
comprehensible, even by a person who knows scarcely any thing of 
geometry ; and every mode of the application of isometrical drawing is 
beautifully illustrated by engravings." — Loudon's Architectural Magazine. 
"Mr. Sopwith commences with a general chapter on 'Mineral Plans 
and Surveys,' in which he enforces at great length, and with no small 
ability, the importance of ' a more general and scientific system of record- 
ing the progress of mineral works in the great coal and lead mining 
districts of the United Kingdom.' The measures expedient to be taken 
for the establishment of a better system are treated of by Mr. Sopwith 
under five different heads. The proprietors and conductors of mines, and 
all under them, would do well to study the whole of these sections atten- 
tively. The author's suggestions are all of a very sensible and practical 
character ; accompanied with every necessary instruction for carrying 
them into complete effect." — "We are, upon the whole, very much pleased 
with Mr. Sopwith's 'Treatise;' it is not only the fullest, but, in point 
of PRACTICAL illustration, the best which has yet appeared 
on the subject of isometrical projection; and from its popular 
style, and the elegance of its embellishments, is eminently calculated to 
extend the use of this very superior method of graphic delineation." — 
Mechanics' Magazine. 



GEOLOGICAL SECTIONS OF MINES IN ALSTON 
MOOR AND TEESDALE; shewing the various Strata and 
Subterranean Operations. Engraved on three Copperplates, 
24 Inches by 12 Inches, 17 Inches by 7 Inches, and 20 Inches 
by 10 Inches, and coloured, with Letter-press Decription, &c 
By T. Sopwith. Price 10s. 6d. 



3 

AN ACCOUNT OF THE MINING DISTRICTS OF 
ALSTON MOOR, WEARDALE, AND TEESDALE, IN 
CUMBERLAND AND DURHAM; comprising descriptive 
Sketches of the Scenery, Antiquities, Geology, and Mining 
Operations in the upper Dales of the Rivers Tyne, Wear, and 
Tees. By T. Sopwith. Price 4s. 6d. 

" To all who are desirous of having some practical knowledge of geology 
and mining, and who can spare a month to walk over Alston Moor and 
the other districts, we most strongly recommend this little work as a 
companion. We do not know any manner in which a young architect, 
engineer, or land-surveyor, could spend a month's holidays with more 
advantage, either to his mind or to his health, than in traversing such a 
district." — Loudon's Architectural Magazine. 

" This is such a work as we have long wished to see. Happily, the 
subject has fallen into the hands of a practical man, and not a mere 
amateur of ores, or a panegyrist of the picturesque. We earnestly recom- 
mend to those who are planning a tour, to think well on the beauties, and 
ponder on the profits of a campaign among the mines. To such persons 
this book will be of great value. The work, in its 'getting up,' does 
credit to the provincial press." ■ • The practical operation of mining itself, 
with a comparison of the ancient and modern modes, and some hints as to 
the ways and means of a miner's existence, lead us to the chapter headed 
* A Visit to a Lead Mine,' the whole of which we would extraet if our 
space would permit ; but we must content ourselves with remarking, that 
the circumstances of many mines are here crowded into one picture, and 
grouped with such effect that we see and feel as we read. Yard moss, 
Cauldron Snout, and the Dale scenery are admirably described." — Atlas. 



PLAN OF THE MINING DISTRICT OF ALSTON 
MOOR, WITH PART OF THE DALES OF TYNE, 
WEAR, AND TEES, and the several new Roads recently 
made in these Districts. By T. Sopwith. Engraved on 
Copperplate, Is. 6d. plain, 2s. 6d. coloured. 



EIGHT VIEWS OF FOUNTAINS ABBEY, illustrating 
the Architectural and Picturesque Beauties of that celebrated 
Ruin. Engraved on Copperplate from original Drawings. 
With a HISTORICAL AND ARCHITECTURAL DE- 
SCRIPTION, by T. Sopwith. Royal Folio, 10s. 6d. 

" The sketch conveys all the general idea of Fountains that tourist or 
antiquary can wish, detailed with truth, spirit, and feeling." — Letter from 
R. Surtees, Esq., Author of the History of Durham. 



A HISTORICAL AND DESCRIPTIVE ACCOUNT 

OF ALL SAINTS' CHURCH, in Newcastle upon Tyne ; 
with Plans, Views, and Architectural Details; an Account of 
the Monuments, with Armorial Bearings, &c. By T. Sopwith. 
Demy 8vo. ; 11 Copperplate Engravings; 10s. 6d. 

" Though this may be considered a local work, yet it goes so much into 
detail, and gives such accurate plans, sections, views, estimates, &c. of 
the church, that it is calculated to be of considerable use to the young 
architect." — Loudon's Architectural Magazine. 

This work being chiefly of local interest, nearly the whole impression 
has been sold, and a few copies only remain. 



PLAN OF THE VALE OF DERWENT, near New- 
castle, shewing the new Line of Road, with a Letter-press 
Description. By T. Sopwith. A large Copperplate Engrav- 
ing, coloured, with Sheet of Letter-press ; 7s. 6d. 



PROJECTING AND PARALLEL RULERS, invented 
by T. Sopwith, for constructing Plans and Drawings in 
Isometrical and other Modes of Projection, with descriptive 
Letter-press, &c. 3s. 6d. 



ISOMETRICAL DRAWING PAPER, for the easy and 
rapid Construction of Plans and Drawings in Isometrical 
Projection. Price Is. per Sheet, or l6s. per Quire. 



DESCRIPTION AND USE OF AN IMPROVED 
LEVELLING STAVE. By T. Sopwith. 

The IMPROVED LEVELLING STAVE may be had as 
above, Price £ each, accompanied with a Letter-press 

Description. 



LIBRARY OF CONGRESS 



019 423 970 1 




